Classifications

• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23D—EDIBLE OILS OR FATS, e.g. MARGARINES, SHORTENINGS, COOKING OILS
  • A23D7/00—Edible oil or fat compositions containing an aqueous phase, e.g. margarines
  • A23D7/02—Edible oil or fat compositions containing an aqueous phase, e.g. margarines characterised by the production or working-up
  • A23D7/04—Working-up
  • A23D7/05—Working-up characterised by essential cooling
• • A—HUMAN NECESSITIES
  • A23—FOODS OR FOODSTUFFS; TREATMENT THEREOF, NOT COVERED BY OTHER CLASSES
  • A23D—EDIBLE OILS OR FATS, e.g. MARGARINES, SHORTENINGS, COOKING OILS
  • A23D7/00—Edible oil or fat compositions containing an aqueous phase, e.g. margarines
  • A23D7/015—Reducing calorie content; Reducing fat content, e.g. "halvarines"

Definitions

• the present invention is concerned with a dispersion comprising a continuous fat phase and a dispersed gelled aqueous phase, and a process for preparing such dispersion.
• the present invention relates to a water-in-oil dispersion of extremely low fat content, such as for instance a spread containing from 5 to 30 wt.% fat and a dispersed gelled aqueous phase.
• European patent application no. 0 237 120 spreads comprising less than 35 wt.% fat and a gel-forming aqueous phase having a relatively high viscosity are described. These spreads are prepared by admixing the aqueous phase and fat phase at a temperature of 60° or 70°C and further processing the emulsion so obtained through two cooled C-units or alternatively through a sequence of two cooled A-units followed by a high shear mixer. European patent application no. 0 237 120 furthermore describes very low fat spreads containing substantial amounts of iota- or kappa-carrageenan.
• European patent application 0 279 499 describes edible fat-continuous dispersions having a fat content of less than 30% by weight and containing an aqueous phase having a viscosity of less than 400 mPa.s at 35°C and a shear rate of 1000 s ⁇ 1 and containing less than 200 ppm amino acid residues, calculated on the weight of the aqueous phase.
• stable water-in-oil dispersions having very advantageous properties can be prepared by cooling a water-continuous composition containing in combination (i) a gelling amount of one or more gelling polysaccharides capable of forming a reversible gel, and (ii) a significant amount of amino acid residues, to a temperature below the gel setting temperature during a sufficiently long period of time to allow the formation of a gel structure, subjecting said water-continuous composition to shear so as to convert it into small gelled aqueous beads and forming a fat-continuous dispersion.
• one aspect of the present invention is a process for preparing a dispersion comprising a continuous fat phase and a dispersed gelled aqueous phase, wherein a water-continuous composition, containing, calculated on the water:
• a reversible gel is meant an aqueous gel that melts when heated and again forms a gel when cooled down subsequently.
• gelling polysaccharides capable of forming reversible gels are: agar, carrageenan, furcelleran, gellan, etc.
• the gel setting temperature as referred to in this application is meant the temperature at which, upon slowly cooling down, an ordered gel structure is formed.
• the gel setting temperature of an aqueous composition can be determined by heating the composition to above the gel melting point, splitting it up in a number of samples which are subsequently equilibrated, under quiescent conditions, at different temperatures lying 1 centigrade apart, and putting a steel ball of about 1 mm diameter on each of the samples after equilibration during 15 minutes. If the samples are ordered in accordance with the temperature at which the samples were equilibrated, starting from the sample equilibrated at the highest temperature, the gel setting temperature is the equilibration temperature of the first sample through which the steel ball does not sink.
• the melting temperature of a gel can suitably be measured using the following procedure: Pour a sample into a glass test tube and allow it to set fully at 5°C. Then place the tube in a water jacket connected to a programmable water bath. Place a steel ball, having a diameter of approximately 1 mm, on the surface of the sample and depress slightly in order to minimize surface tension effects. Equilibrate for one hour at 25°C, or a lower temperature in case of a low melting gel, and then apply a heating 13, of 0.05°C/min. The gel melting point is the temperature at which the ball begins to sink through the sample. Movement of the ball can be observed using a travelling microscope.
• the process according to the invention offers the advantage that it enables the simple preparation of water-in-oil dispersions of very low fat content.
• the latter dispersions moreover are stable under storage conditions and destabilize readily in the mouth, due to the presence of a significant amount of amino acid residues.
• the gel structure present in the aqueous phase stabilizes the dispersion and prevents the formation of a water-continuous system which would spontaneously occur in the absence of such structure.
• the gel structure becomes less rigid and the destabilizing influence of the amino acid residues becomes more manifest. Accordingly at mouth temperature the present fat-continuous dispersion will become unstable and invert to a water-continuous system, thereby releasing its flavour.
• the presence of a gel structure in the water-continuous composition used in the present process provides the fat-continuous system formed with sufficient structure to prevent it from re-inverting to a water-continuous composition.
• a gel structure is only formed after the formation of a fat-continuous emulsion, the risk of re-inversion, in particular in the presence of substantial amounts of amino acid residues, is much higher than in the present process.
• Yet another advantage of the present process is the fact that it makes it possible to control the aqueous phase droplet size distribution in the final dispersion.
• the droplet size distribution of the aqueous phase is very important as regards the oral response, appearance and stability of water-in-oil dispersions. Also the release of flavour components from the dispersed aqueous phase is largely determined by the droplet size distribution of said aqueous phase.
• the present invention relates to a process for the preparation of a dispersion comprising from 5-30 % by weight of a continuous fat phase and from 70-95 % by weight of a dispersed gelled aqueous phase.
• the present process enables the preparation of stable dispersions containing substantially less than 25 % by weight of fat.
• Food products based on a dispersion having so low a fat content are particularly desirable because of their low calorific content.
• the process relates to a process for preparing an edible dispersion comprising from 8-27 wt.% continuous fat phase and 92-73 wt.% dispersed gelled aqueous phase.
• the gelled beads formed in the present process can be difficult to visualize as in the present process the fat-continuous dispersion is normally formed before the gelation process is completed. As long as the gelation process is not completed, the gelled beads formed, when kept under quiescent conditions at below the gel melting temperature as is normally required if the gel beads are to be visualized by means of, for instance, a microscope, will tend to coalesce by cross-linking.
• the term 'fat' refers to edible fatty substances in a general sense, including natural or synthesized fats and oils consisting essentially of triglycerides such as, for example, soybean oil, sunflower oil, palm oil, coconut oil, fish oil, lard and tallow, which may have been partially or completely hydrogenated or modified otherwise, as well as non-toxic fatty materials having properties similar to triglycerides, which materials may be indigestible, such as for example waxes, e.g. jojoba oil and hydrogenated jojoba oil, and polyol fatty acid polyesters referred to hereinafter in more detail.
• the terms fat and oil are used interchangeably.
• polyol' is intended to refer to any aliphatic or aromatic compound which comprises at least four free hydroxyl groups.
• Such polyols in particular include the group of sugar polyols, which comprises the sugars, i.e. the mono-, di- and oligosaccharides, the corresponding sugar alcohols and the derivatives thereof having at least four free hydroxyl groups.
• sugar polyols examples include glucose, mannose, galactose, xylose, fructose, sorbose, tagatose, ribulose, xylulose, maltose, lactose, cellobiose, raffinose, sucrose, erythritol, mannitol, lactitol, sorbitol, xylitol and alpha-methylglucoside.
• a generally used and preferred sugar polyol is sucrose.
• 'polyol fatty acid polyester' is intended to refer to any such polyesters or mixtures thereof of which, on an average, more than 70 % of the polyol hydroxyl groups have been esterified with fatty acids.
• 'indigestible' is meant that at least about 70 % by weight of the material concerned is not digested by the human body.
• the present process can very advantageously be employed in the production of spreads of very low fat content.
• the spreads prepared by the present process even when having a fat content as low as about 20 wt.%, have an oral response which is very much like commercially available spreads comprising about 40 wt.% fat. Furthermore these spreads are found to be easy spreadable and do not loose water on spreading.
• the water-continuous composition is maintained at a sufficiently low temperature for such a period of time that the cross-linking mechanism leading to gelation starts to occur.
• the cooling alloy and residence time employed till the formation of the fat-continuous dispersion are such that under quiescent conditions a gel having a shear modulus of more than 50 Pa., preferably of more than 70 Pa., would have formed.
• the following method can suitably be used to determine the shear modulus: Fit a Bohlin VOR Rheometer, or equivalent apparatus, with a 30 mm plate and 5 degree cone geometry. Heat the sample to a temperature at least 10°C above its gel melting temperature and then bring it to the starting temperature employed in the process. Place the liquid sample to be tested between the cone and the plate and set the gap at the plate edge to be 1 mm. Apply silicone oil to the plate edge to prevent the sample from drying out.
• the conversion of the water-continuous composition to small gelled aqueous beads can suitably be effected by means of several devices known in the art.
• suitable devices are: VotatorsTM (A-units), crystallizers (C-units), static mixers, Ultra TuraxTM mixers, etc.
• the conversion is effected by means of one or more devices in which the water-continuous composition can be cooled and/or subjected to shear.
• at least one of these devices is provided with rotating means for imparting shear to said composition.
• the gelled beads have been reduced to a relatively small size. Accordingly in a preferred embodiment of the invention the water-continuous composition is converted to small gelled aqueous beads having a volume weighted mean diameter of less than 150 micrometer (microns) prior to the formation of the fat-continuous dispersion.
• the formation of the fat-continuous dispersion can suitably be accomplished by two alternative routes.
• the first route is a process wherein the water-continuous composition contains from 5 to 27 % by weight of dispersed fat and is inverted to a fat-continuous dispersion after the fat-containing water-continuous composition has been converted to gelled aqueous beads.
• the term 'inversion' is used here to indicate that a water-continuous system containing a dispersed fat phase is converted into a water-in-oil dispersion.
• Such a water-continuous system in accordance with the invention can be composed of numerous small gelled aqueous beads containing dispersed fat droplets.
• the inversion of a water-continuous composition to a water-in-oil dispersion in the present process is normally not an instantaneous event.
• the inversion of a water-continuous fat-containing composition to a water-in-oil dispersion can involve the formation of a transient bi-continuous system or a transient system which is partly fat- and partly water-continuous.
• the second route is a process wherein the water-continuous composition after having been converted to small gelled aqueous beads is combined with a separate fat-continuous stream to form a fat-continuous dispersion.
• This process differs from the first route in that the fat is added after the aqueous phase composition of the final dispersion has been converted to gelled aqueous beads.
• the aqueous phase composition may already contain some dispersed fat, it is preferred that the bulk of the fat as present in the final dispersion is added in a separate fat-continuous stream after the gelled aqueous beads have been formed.
• the combination of the water-continuous with the fat-continuous stream preferably is carried out in such a manner that a fat-continuous system is formed, rather than a water-continuous system which additionally needs to be inverted to the final water-in-oil dispersion. If, as is the case in the present process, the gelled beads to be combined with the fat are sufficiently structured, the fat can easily be worked around the gelled beads to form a fat-continuous dispersion.
• the further steps required to form a water-in-oil dispersion preferably involve the application of shear to either invert the fat-containing gelled beads, or alternatively to thoroughly admix the gelled beads and the fat stream. Since these shear conditions may reduce the average size of the gelled beads, it is not necessary that, before formation of the fat-continuous dispersion, the gelled beads are of the size aimed for in the final prodcut. thus the gelled beads may be relatively large before incorporation, however generally have a size of less than 150 micrometer (microns).
• the gelled beads are relatively small before the formation of the fat-continuous dispersion as it is more convenient to control the size of the beads before the formation of the fat-continuous dispersion than during the inversion or admixing.
• the gelled beads have a volume weighted mean diameter of less than 100 micrometer (microns), more preferably of less than 70 micrometer (microns), prior to the formation of the fat-continuous dispersion.
• Another aspect of the present invention is an edible dispersion containing less than 30% by weight of a continuous fat phase and at least 70 wt.% of a gelled aqueous phase, wherein the aqueous phase contains (i) one or more gelling polysaccharides, capable of forming a reversible gel, at a concentration level of 1 to 6 times the critical concentration of said gelling polysaccharide(s), and (ii) more than 200 ppm amino acid residues.
• the dispersions according to the present invention are stable, ie. they do not display water- or oil exudation even when subjected to temperature cycling nor do they loose water on spreading. Furthermore the present spreads have a significantly better oral response than spreads of similar fat content described in the prior art. This improved oral response may be explained from the presence of a significant amount of amino acid residues, particularly protein, in combination with a melting gel structure.
• the gel structure stabilizes the product structure in the lower temperature-range normally encountered during storage. At higher temperatures i.e. in the temperature range above 30°C, the gel structure will become less manifest and the destabilizing influence of the amino acid residues will promote the inversion to a water-continuous system. The latter inversion is necessary to release the flavour components present in the dispersed aqueous phase.
• the present dispersion is characterized by the fact that NMR measurements of the volume weighted mean droplet size show a relatively broad droplet diameter distribution.
• the droplet diameter distribution can suitably be measured by means of NMR (see J. Colloid and Interface Science 40 (1972), 206 and 93 (1983), 521) using a log-normal distribution as is commonly employed for particle size analysis.
• the dispersion made through the present process as contrasted to dispersions of identical composition but prepared by means of conventional processing, show a broad droplet diameter distribution as illustrated by the figure found for sigma, which generally exceeds 0.9 micrometer (microns).
• Another aspect of the invention is therefore concerned with an edible dispersion containing less than 30% by weight of a continuous fat phase and at least 70 wt.% of a gelled aqueous phase, wherein sigma for the aqueous phase droplet diameter distribution exceeds 0.9 micrometer (microns) and the aqueous phase contains one or more gelling polysaccharides, capable of forming a reversible gel, at a concentration level of 1 to 6 times the critical concentration of said gelling polysaccharide(s).
• the high figures observed for the parameter sigma may be indicative of the fact that the aqueous phase in the present dispersion exhibits a bimodal droplet-distribution. According to a very preferred embodiment of the invention sigma exceeds 1.1 micrometer (microns).
• the gelling polysaccharide present in the dispersion is selected from the group consisting of kappa-carrageenan, iota-carrageenan, agar, furcelleran, gellan and mixtures thereof. Most preferably the gelling polysaccharide is kappa-carrageenan, iota-carrageenan or a mixture thereof.
• the aqueous phase of the dispersion contains a carrageenan gel structure having a transition midpoint temperature below 45°C, more preferably below 40°C.
• the desired transition midpoint temperature can be obtained by adjusting the cationic concentration and composition of the aqueous phase.
• the midpoint temperature of the transition from ordered to disordered state can suitably be determined by measuring the optical rotation as described in Faraday Discuss. Chem. Soc. (1974) 57 , 230-237.
• the use of a low-melting gel structure in the present dispersion offers the advantage that the dispersion destabilizes readily in the mouth. Spreads containing a low-melting gel structure consequently can have a very favourable oral response.
• the aqueous phase contains more than 300 ppm amino acid residues.
• amino acid residues as used throughout this document includes intact as well as denatured protein di- and oligopeptides and free amino acid groups.
• the dispersion according to the invention contains more than 500 ppm amino acid residues, calculated on the aqueous phase.
• amino acid residues present in the dispersion according to the invention are protein(s).
• proteins that may advantageously be included in the present dispersion are: gelatin, milk protein (e.g. skim milk protein, whey protein, casein) and soy protein.
• the present dispersion in addition to the gelling polysaccharide(s), can suitably contain gelling components other than polysaccharides that form reversible gels, such as for instance gelatin, alginates, pectin, whey protein, starch, starch derivatives, soy protein, bovine serum protein or microcrystalline cellulose.
• gelling components other than gelling polysaccharides capable of forming reversible gels at a concentration level below 2 times, preferably below 1 time the critical concentration of said gelling component(s).
• the present dispersion can furthermore contain ingredients such as emulsifiers, thickeners, colourings, flavourings etc.
• ingredients such as emulsifiers, thickeners, colourings, flavourings etc.
• thickening agents that can suitably be used in the present dispersion are locust bean gum, gaur gum, xanthan gum and alginate salts of monovalent cations.
• the critical concentration of a gelling agent is the concentration level at which said gelling agent will start to form a gel.
• the critical concentration of the gelling polysaccharide(s) in the aqueous phase of the present dispersion is determined in an aqueous system which has exactly the same composition as the aqueous phase to be incorporated into the spread (except for the absence of gelling components other than polysaccharides capable of forming reversible gels, which optionally may be included therein and with the exception of the water content and the concentration of gelling agent which have to be varied to establish the critical concentration).
• the critical concentration of a gelling agent or a mixture of gelling agents in a particular composition can be calculated from measurements of the shear modulus of a series of samples containing different concentrations of gelling agent or mixture of gelling agents, as described in Br. Polymer J. 17 (1985), 164. If the critical concentration of a combination of gelling agents is to be determined, then the critical concentration of such mixture of gelling agents is determined in a manner analogous to the procedure described above. The composition of the mixture of gelling agents is kept constant and the weight concentration of said mixture is varied as if it consisted of only one single gelling agent.
• the aqueous phase contains a gelling polysaccharide, capable of forming a reversible gel, at a concentration level of 1.2 to 5 times, more preferably of 1.5 to 4.5 the critical concentration thereof.
• the process according to the invention enables the preparation of dispersions without the necessity of utilizing highly viscous aqueous phase compositions.
• dispersions comprising an aqueous phase having a relatively low viscosity can be prepared.
• Such dispersions are less thick in the mouth than dispersions having a highly viscous aqueous phase and moreover destabilize more rapidly in the mouth.
• the gelled aqueous phase has a viscosity of less than 30 mPa., more preferably less than 20 mPa.s at 5°C and a shear rate of 17090 s ⁇ 1.
• the viscosity can suitably be measured in a Ferranti Berry Viscometer TM, with a standard cone having a diameter of 7 cm, using the method described on page 3 of EP-A 0 237 120.
• the size of the gelled aqueous phase droplets to a large extent determines the appearance, oral response and rheology of the dispersion.
• these gelled droplets have a number weighted mean diameter of less than 50 micrometer (microns), preferably of less than 30 micrometer (microns).
• a spread containing 20 wt.% of a continuous fat phase and 80 wt.% of a dispersed gelled aqueous phase was prepared from a water-continuous emulsion obtained by admixing an oil phase and aqueous phase of the following composition:
• the water-continuous emulsion obtained after admixture of the above two phases at 45°C was passed through a scraped surface heat exchanger (in this case a VotatorTM cooled by means of ethylene glycol; also called an A-unit) and a cooled crystallizer (C-units) after which the product was filled into tubs. Inversion of the water-continuous emulsion to a fat-continuous dispersion was obtained in the cooled C-unit.
• a scraped surface heat exchanger in this case a VotatorTM cooled by means of ethylene glycol; also called an A-unit
• C-units cooled crystallizer
• the fat-continuous spread so obtained was found to be easy spreadable and did not loose water on spreading.
• the product had a conductivity at 5°, 10°, 15° and 20°C of respectively 28, 120, 230 and 170 micro-Siemens/cm, indicating that it contained a continuous fat phase and a discontinuous aqueous phase.
• the volume weighted mean diameter was determined by means of pulse NMR and found to be 6 micrometer (microns), sigma was measured as 1.1 micrometer (microns).
• the hardness-values of the product at 5°C as determined by means of a cone penetrometer was found to be 210 g/cm2.
• Example 1 was repeated with the exception that the aqueous phase additionally contained 0.1 % gelatin, by weight of water.
• the precise processing conditions were as follows:
• the fat-continuous spread so obtained was found to be spreadable and did not loose water on spreading.
• the product had a conductivity at 5°, 10°, 15° and 20°C of respectively 230, 210, 300 and 300 micro-Siemens/cm, indicating that it contained a continuous fat phase and a discontinuous aqueous phase.
• the volume weighted mean diameter was determined by means of pulse NMR and found to be 17 micrometer (microns), sigma was found to be 1.2 micrometer (microns).
• the hardness-values of the product at 5° and 10°C, as determined by means of a cone penetrometer were found to be 255 and 230 g/cm2.

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• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Food Science & Technology (AREA)
• Polymers & Plastics (AREA)
• Edible Oils And Fats (AREA)
• Colloid Chemistry (AREA)
• Emulsifying, Dispersing, Foam-Producing Or Wetting Agents (AREA)

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• 1990
  • 1990-05-04 EP EP90201124A patent/EP0398412B1/en not_active Revoked
  • 1990-05-04 DE DE9090201124T patent/DE69001198T2/de not_active Revoked
  • 1990-05-14 CA CA002016712A patent/CA2016712C/en not_active Expired - Fee Related
  • 1990-05-14 FI FI902385A patent/FI902385A0/fi not_active Application Discontinuation
  • 1990-05-14 AU AU54979/90A patent/AU621485B2/en not_active Ceased
  • 1990-05-15 ZA ZA903703A patent/ZA903703B/xx unknown
  • 1990-05-15 NO NO902164A patent/NO175342C/no unknown
  • 1990-05-15 IE IE174790A patent/IE66343B1/en not_active IP Right Cessation
  • 1990-05-16 JP JP2124316A patent/JPH0832302B2/ja not_active Expired - Lifetime
  • 1990-05-16 TR TR00459/90A patent/TR27369A/xx unknown

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